1. Field of the Invention
The present invention relates to an aerodynamic surface geometry for a golf ball. More specifically, the present invention relates to a golf ball having a lattice structure and an innersphere.
2. Description of the Related Art
Golfers realized perhaps as early as the 1800""s that golf balls with indented surfaces flew better than those with smooth surfaces. Hand-hammered gutta-percha golf balls could be purchased at least by the 1860""s, and golf balls with brambles (bumps rather than dents) were in style from the late 1800""s to 1908. In 1908, an Englishman, William Taylor, received a British patent for a golf ball with indentations (dimples) that flew better ad more accurately than golf balls with brambles. A.G. Spalding and Bros., purchased the U.S. rights to the patent (embodied possibly in U.S. Pat. No. 1,286,834 issued in 1918) and introduced the GLORY ball featuring the TAYLOR dimples. Until the 1970s, the GLORY ball, and most other golf balls with dimples had 336 dimples of the same size using the same pattern, the ATTI pattern. The ATTI pattern was an octohedron pattern, split into eight concentric straight line rows, which was named after the main producer of molds for golf balls.
The only innovation related to the surface of a golf ball during this sixty year period came from Albert Penfold who invented a mesh-pattern golf ball for Dunlop. This pattern was invented in 1912 and was accepted until the 1930""s. A combination of a mesh pattern and dimples is disclosed in Young, U.S. Pat. No. 2,002,726, for a Golf Ball, which issued in 1935.
The traditional golf ball, as readily accepted by the consuming public, is spherical with a plurality of dimples, with each dimple having a circular cross-section. Many golf balls have been disclosed that break with this tradition, however, for the most part these non-traditional golf balls have been commercially unsuccessful.
Most of these non-traditional golf balls still attempt to adhere to the Rules Of Golf as set forth by the United States Golf Association (xe2x80x9cUSGAxe2x80x9d) and The Royal and Ancient Golf Club of Saint Andrews (xe2x80x9cRandAxe2x80x9d). As set forth in Appendix III of the Rules of Golf, the weight of the ball shall not be greater than 1.620 ounces avoirdupois (45.93 gm), the diameter of the ball shall be not less than 1.680 inches (42.67 mm) which is satisfied if, under its own weight, a ball falls through a 1.680 inches diameter ring gauge in fewer than 25 out of 100 randomly selected positions, the test being carried out at a temperature of 23xc2x11xc2x0 C., and the ball must not be designed, manufactured or intentionally modified to have properties which differ from those of a spherically symmetrical ball.
One example is Shimosaka et al., U.S. Pat. No. 5,916,044, for a Golf Ball that discloses the use of protrusions to meet the 1.68 inch (42.67mm) diameter limitation of the USGA and RandA. The Shimosaka patent discloses a golf ball with a plurality of dimples on the surface and a few rows of protrusions that have a height of 0.001 to 1.0 mm from the surface. Thus, the diameter of the land area is less than 42.67 mm.
Another example of a non-traditional golf ball is Puckett et al., U.S. Pat. No. 4,836,552 for a Short Distance Golf Ball, which discloses a golf ball having brambles instead of dimples in order to reduce the flight distance to half of that of a traditional golf ball in order to play on short distance courses.
Another example of a non-traditional golf ball is Pocklington, U.S. Pat. No. 5,536,013 for a Golf Ball, which discloses a golf ball having raised portions within each dimple, and also discloses dimples of varying geometric shapes such as squares, diamonds and pentagons. The raised portions in each of the dimples of Pocklington assists in controlling the overall volume of the dimples.
Another example is Kobayashi, U.S. Pat. No. 4,787,638 for a Golf Ball, which discloses a golf ball having dimples with indentations within each of the dimples. The indentations in the dimples of Kobayashi are to reduce the air pressure drag at low speeds in order to increase the distance.
Yet another example is Treadwell, U.S. Pat. No. 4,266,773 for a Golf Ball, which discloses a golf ball having rough bands and smooth bands on its surface in order to trip the boundary layer of air flow during flight of the golf ball.
Aoyama, U.S. Pat. No. 4,830,378, for a Golf Ball With Uniform Land Configuration, discloses a golf ball with dimples that have triangular shapes. The total flat land area of Aoyama is no greater than 20% of the surface of the golf ball, and the objective of the patent is to optimize the uniform land configuration and not the dimples.
Another variation in the shape of the dimples is set forth in Steifel, U.S. Pat. No. 5,890,975 for a Golf Ball And Method Of Forming Dimples Thereon. Some of the dimples of Steifel are elongated to have an elliptical cross-section instead of a circular cross-section. The elongated dimples make it possible to increase the surface coverage area. A design patent to Steifel, U.S. Pat. No. 406,623, has all elongated dimples.
A variation on this theme is set forth in Moriyama et al., U.S. Pat. No. 5,722,903, for a Golf Ball, which discloses a golf ball with traditional dimples and oval shaped dimples.
A further example of a non-traditional golf ball is set forth in Shaw et al., U.S. Pat. No. 4,722,529, for Golf Balls, which discloses a golf ball with dimples and 30 bald patches in the shape of a dumbbell for improvements in aerodynamics.
Another example of a non-traditional golf ball is Cadomiga, U.S. Pat. No. 5,470,076, for a Golf Ball, which discloses each of a plurality of dimples having an additional recess. It is believed that the major and minor recess dimples of Cadomiga create a smaller wake of air during flight of a golf ball.
Oka et al., U.S. Pat. No. 5,143,377, for a Golf Ball, discloses circular and non-circular dimples. The non-circular dimples are square, regular octagonal, regular hexagonal and amount to at least forty percent of the 332 dimples on the golf ball of Oka. These non-circular dimples of Oka have a double slope that sweeps air away from the periphery in order to make the air turbulent.
Machin, U.S. Pat. No. 5,377,989, for Golf Balls With Isodiametrical Dimples, discloses a golf ball having dimples with an odd number of curved sides and arcuate apices to reduce the drag on the golf ball during flight.
Lavallee et al., U.S. Pat. No. 5,356,150, discloses a golf ball having overlapping elongated dimples to obtain maximum dimple coverage on the surface of the golf ball.
Oka et al., U.S. Pat. No. 5,338,039, discloses a golf ball having at least forty percent of its dimples with a polygonal shape. The shapes of the Oka golf ball are pentagonal, hexagonal and octagonal.
Although the prior art has set forth numerous variations for the surface of a golf ball, there remains a need for a golf ball having a surface that minimizes the volume needed to trip the boundary layer of air at low speed while providing a low drag level at high speeds.
The present invention is able to provide a golf ball that meets the USGA requirements, and provides a minimum land area to trip the boundary layer of air surrounding a golf ball during flight in order to create the necessary turbulence for greater distance. The present invention is able to accomplish this by providing a golf ball with an outersphere defined by a lattice structure and an innersphere.
One aspect of the present invention is a golf ball with an innersphere having a surface and a plurality of lattice members that define an outersphere. Each of the lattice members has a cross-sectional contour with an apex at the greatest extent from the center of the golf ball, which define the outersphere. The plurality of lattice members are connected to each other to form a predetermined pattern on the golf ball.
The plurality of lattice members on the golf ball may cover between 20% to 80% of the golf ball. The apex of each of the plurality of lattice members has a width less than 0.00001 inch resulting in a minimal land area for the outersphere. The diameter of the innersphere may be at least 1.67 inches and the apex of each of the plurality of lattice members may have a distance of at least 0.005 inch from the bottom of the lattice member resulting in a diameter of the outersphere of at least 1.68 inches. The golf ball may also include a plurality of smooth portions on the innersphere surface wherein the plurality of smooth portions and the plurality of lattice members cover the entire golf ball.
Another aspect of the present invention is a golf ball having an innersphere with a surface and a plurality of lattice members with apices that define an outersphere. Each of the lattice members has a cross-sectional curvature with an arc. Each of the plurality of lattice members is connected to each other to form a plurality of interconnected polygons. The lattice members cover between 20% and 80% of the golf ball.
Yet another aspect of the present invention is a golf ball having a sphere with a tubular lattice configuration. The sphere has a diameter in the range of 1.60 to 1.70 inches. The tubular lattice configuration includes a plurality of lattice members. Each of the lattice members has an apex that has a distance from the bottom of each lattice member in a range of 0.005 to 0.010 inch resulting in an outersphere with a diameter of at least 1.68 inches.
A further aspect of the present invention is a non-dimpled golf ball having an innersphere and a plurality of lattice members with apices that define an outersphere. The innersphere has a diameter in the range of 1.60 to 1.70 inches. Each of the lattice members has an apex with a distance from the bottom of each lattice member in a range of 0.005 to 0.010 inch resulting in an outersphere with a diameter of at least 1.68 inches. The entire surface of the golf ball is composed of the plurality of lattice members and a plurality of smooth portions.